564 research outputs found
Magnetic properties of a spin-1 Triangular Ising system
We studied some magnetic behaviors of Blume-Capel (BC) model in a site
diluted triangular lattice by means of the effective-field theory (EFT) with
correlations. The effects of the exchange interaction (J), crystal field (D),
concentration (p) and temperature (T) on the magnetic properties of spin-1 BC
model in a triangular lattice such as magnetization, susceptibility, phase
diagram and hysteresis behaviors are investigated, in detail. The phase
diagrams of the system are presented in two different planes. The tricritical
point as well as tetracritical and critical end special points are found as
depending on the physical parameters of the system. Moreover, when the
hysteresis behaviors of the system are examined, the single and double
hysteresis loop are observed for various values of the physical parameters. We
show that the hysteresis loops have different coercive field points in which
the susceptibility make peak at these points
Domain Wall Depinning in Random Media by AC Fields
The viscous motion of an interface driven by an ac external field of
frequency omega_0 in a random medium is considered here for the first time. The
velocity exhibits a smeared depinning transition showing a double hysteresis
which is absent in the adiabatic case omega_0 --> 0. Using scaling arguments
and an approximate renormalization group calculation we explain the main
characteristics of the hysteresis loop. In the low frequency limit these can be
expressed in terms of the depinning threshold and the critical exponents of the
adiabatic case.Comment: 4 pages, 3 figure
Comparison of chemotherapy and hematopoietic stem cell transplantation pre and postterm DMFT scores: A preliminary study
Aims: Chemotherapy is frequently used as a conditioning regimen to destroy malignant marrow cells before transplantation. Xerostomia, dysphagia, altered taste perception, mucositis, soft‑tissue ulceration, and infection are common adverse oral effects of chemotherapy. The study was aimed to compare decayed, missing, filled teeth (DMFT) scores before and after hematopoietic stem cell transplantation (HSCT) and chemotherapy.Materials and Methods: Thirty‑six patients undergoing HSCT were included in the study. Apre‑HSCT dental treatment protocol was implemented that consisted of restoration of all active carious lesions, treatment of periodontal infections, and extraction of all teeth with advanced periodontal disease. Upon completion of dental treatment, the importance of rigorous and effective oral hygiene was reemphasized, and patients were recalled 6 months later. DMFT scores were calculated prior to the initiation of HSCT treatment and 6 months after transplantation.Statistical Analysis Used: Regression analysis was used to evaluate the effects of HSCT and chemotherapy on DMFT scores.Results: Wilcoxon T test showed a statistically significant difference in DMFT scores before and after HSCT (P < 0.001). Conclusions: DMFT scores were found to increase after chemotherapy and HSCT, suggesting that the risk of infection is higher among HSCT patients when compared to other individuals. The results emphasize the need for dental examinations as an integral part of examination and treatment planning for patients undergoing HSCT and chemotherapy.Key words: Chemotherapy, decayed missing filled teeth scores, hematopoietic stem cell transplantatio
Melting of Flux Lines in an Alternating Parallel Current
We use a Langevin equation to examine the dynamics and fluctuations of a flux
line (FL) in the presence of an {\it alternating longitudinal current}
. The magnus and dissipative forces are equated to those
resulting from line tension, confinement in a harmonic cage by neighboring FLs,
parallel current, and noise. The resulting mean-square FL fluctuations are
calculated {\it exactly}, and a Lindemann criterion is then used to obtain a
nonequilibrium `phase diagram' as a function of the magnitude and frequency of
. For zero frequency, the melting temperature of the
mixed phase (a lattice, or the putative "Bose" or "Bragg Glass") vanishes at a
limiting current. However, for any finite frequency, there is a non-zero
melting temperature.Comment: 5 pages, 1 figur
Gigantic peripheral osteoma of the mandible: a case report
Osteomas are osteogenic lesions that have a limited growth potential. They are comprised of histologically and
radiographically normal bone. Osteomas are categorized as central, peripheral or extraskeletal according to location. Clinically, peripheral osteomas (PO) are unilateral, sessile or pedunculated and have mushroom-like lesions
ranging from 10 to 40 mm in diameter. Osteomas affecting the mandible are rare. In this report, we presented a
gigantic peripheral mass on the left mandible in a 55-year old patient exhibiting clinical signs related to neoplasia
Facet Formation in the Negative Quenched Kardar-Parisi-Zhang Equation
The quenched Kardar-Parisi-Zhang (QKPZ) equation with negative non-linear
term shows a first order pinning-depinning (PD) transition as the driving force
is varied. We study the substrate-tilt dependence of the dynamic transition
properties in 1+1 dimensions. At the PD transition, the pinned surfaces form a
facet with a characteristic slope as long as the substrate-tilt is
less than . When , the transition is discontinuous and the critical
value of the driving force is independent of , while the transition
is continuous and increases with when . We explain these
features from a pinning mechanism involving a localized pinning center and the
self-organized facet formation.Comment: 4 pages, source TeX file and 7 PS figures are tarred and compressed
via uufile
Phase ordering and roughening on growing films
We study the interplay between surface roughening and phase separation during
the growth of binary films. Already in 1+1 dimension, we find a variety of
different scaling behaviors depending on how the two phenomena are coupled. In
the most interesting case, related to the advection of a passive scalar in a
velocity field, nontrivial scaling exponents are obtained in simulations.Comment: 4 pages latex, 6 figure
Shear bands in granular flow through a mixing length model
We discuss the advantages and results of using a mixing-length, compressible
model to account for shear banding behaviour in granular flow. We formulate a
general approach based on two function of the solid fraction to be determined.
Studying the vertical chute flow, we show that shear band thickness is always
independent from flowrate in the quasistatic limit, for Coulomb wall boundary
conditions. The effect of bin width is addressed using the functions developed
by Pouliquen and coworkers, predicting a linear dependence of shear band
thickness by channel width, while literature reports contrasting data. We also
discuss the influence of wall roughness on shear bands. Through a Coulomb wall
friction criterion we show that our model correctly predicts the effect of
increasing wall roughness on the thickness of shear bands. Then a simple
mixing-length approach to steady granular flows can be useful and
representative of a number of original features of granular flow.Comment: submitted to EP
Passive Sliders on Growing Surfaces and (anti-)Advection in Burger's Flows
We study the fluctuations of particles sliding on a stochastically growing
surface. This problem can be mapped to motion of passive scalars in a randomly
stirred Burger's flow. Renormalization group studies, simulations, and scaling
arguments in one dimension, suggest a rich set of phenomena: If particles slide
with the avalanche of growth sites (advection with the fluid), they tend to
cluster and follow the surface dynamics. However, for particles sliding against
the avalanche (anti-advection), we find slower diffusion dynamics, and density
fluctuations with no simple relation to the underlying fluid, possibly with
continuously varying exponents.Comment: 4 pages revtex
Heating of magnetic fluid systems driven by circularly polarized magnetic field
Cataloged from PDF version of article.A theory is presented to calculate the heat dissipation of a magnetic suspension, a ferrofluid, driven by7 circularly polarized magnetic field. Theory is tested by in vitro experiments and it is shown that, regardless of the character of the relaxation process, linearly and circularly polarized magnetic field excitations, having the same root-mean-square magnitude, are equivalent in terms of heating efficiency. (C) 2010 Elsevier B.V. All rights reserved
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